Focusing anomalies with binary diffractive optical elements.

Binary diffractive optics have been extensively studied to date as tools for arbitrary laser beam shaping and experimentally implemented with etched transparent optics and spatial light modulators. Here we demonstrate that a simple one-step binary optic is able to enhance the intensity of a focused beam, displaying some counterintuitive focusing anomalies. We explain these effects by considering the optical aberrations in binary diffractive optics and outline how this may be exploited for further improvements in refractive/diffractive combinations for super-resolution microscopy.

Instrumentation for ice crystal characterization in laboratory using interferometric out-of-focus imaging.

Airborne characterization of ice crystals has important applications. The extreme difficulty of realizing in situ tests requires the development of a complete instrumentation in the laboratory. Such an installation should enable design, development, test, and calibration of instruments in conditions as close as possible to real ones. We present a set of numerical and experimental tools that have been developed to realize ice crystal sensors based on interferometric particle imaging. The set of tools covers the development of complementary simulators for crystal growth and interferometric particle imaging predictions, experimental generation of "programmable" ice crystals, and instrumentation of a freezing column where different techniques as in-focus imaging, out-of-focus imaging, and digital in-line holography can be combined simultaneously for test and calibration.

Digital micromirror device as programmable rough particle in interferometric particle imaging.

The 2D autocorrelation of the projection of an irregular rough particle can be estimated using the analysis of its interferometric out-of-focus image. We report the development of an experimental setup that creates speckle-like patterns generated by "programmable" rough particles of desired-shape. It should become an important tool for the development of new setups, configurations, and algorithms in interferometric particle imaging.

Duodenal Atresia Associated with Apple Peel Atresia and Situs Inversus Abdominus: A Case Report.

Duodenal atresia is rarely associated with situs inversus abdominus. We report a case of duodenal atresia associated with small bowel atresia of apple peel type and situs inversus abdominus.

[Evaluation of the measurement of capillary glucose concentration versus plasma glucose in the newborn]. / Fiabilité de la mesure de la glycémie capillaire par rapport à la glycémie plasmatique chez le nouveau-né.

BACKGROUND: The reliability of blood glucose monitoring in neonatology is not always confirmed. The aim of this study was to evaluate the reliability of blood glucose measurements made with three different devices in newborns. PATIENTS AND METHODS: The study was prospective, conducted in a medical and neonatal intensive care department over a period of 4 months. Capillary glucose level was measured with three different glucometers and compared with venous glucose level determined using the hexokinase method. An ANOVA and Scheffe test were used for the correlation analysis. RESULTS: Three hundred and nine infants were included, with a mean age of 55h and a mean term of 39 weeks of gestation. Mean blood glucose in the laboratory was 0.62±0.15g/L, 0.71±0.17g/L for Accu-Chek(®) Active, 0.80±0.17g/L for Accu-Chek(®) Performa, and 0.83±0.12g/L for Bionime. An ANOVA showed statistically significant differences between the measurements made by glucometers compared to the reference blood glucose levels, and the Scheffé method showed that glucometers overestimated the real plasma glucose levels. CONCLUSION: None of the devices used in this study was satisfactory. However, an estimation of blood glucose taking into consideration this numerical overestimation would allow early detection of hypoglycemia.

Sanjad-Sakati syndrome in a Tunisian child.

Sanjad-Sakati syndrome (SSS) (OMIM 241410) is a rare autosomal recessive disorder characterized by congenital hypoparathyroidism with growth and mental retardation associated with seizures and a characteristic physiognomy. SSS molecular pathology has been shown to be due to mutations in the TBCE gene on chromosome 1q42-q43. All affected patients of Arab origin are homozygous for a 12-bp (155-166del) deletion in exon 3 of this gene. We report on a Tunisian child with SSS who was homozygous for the 155-166del mutation. Our findings provide additional support of the common (155-166del) deletion founder effect in exon 3 of the TBCE gene in Arab patients. It is very likely that this mutation originated in the Middle East and was introduced in Tunisia by the Banu Hilal invaders.

[Evaluation of administration errors of injectable drugs in neonatology]. / Évaluation des erreurs d'administration des médicaments injectables en néonatologie.

OBJECTIVE: Use of injectable drugs in newborns represents more than 90% of prescriptions and requires special precautions in order to ensure more safety and efficiency. The aim of this study is to gather errors relating to the administration of injectable drugs and to suggest corrective actions. METHODS: This descriptive and transversal study has evaluated 300 injectable drug administrations in a neonatology unit. Two hundred and sixty-one administrations have contained an error. Data are collected by direct observations of administrative act. RESULTS: Errors observed are: an inappropriate mixture (2.6% of cases); an incorrect delivery rate (33.7% of cases); incorrect dilutions (26.7% of cases); error in calculation of the dose to be injected (16.7% of cases); error while sampling small volumes (6.3% of cases); error or omission of administration schedule (1% of cases). CONCLUSION: These data have enabled us to evaluate administration of injectable drugs in neonatology. Different types of errors observed could be a source of therapeutic inefficiency, extended lengths of stay or iatrogenic drug. Following these observations, corrective actions have been undertaken by pharmacists and consist of: organizing training sessions for nursing; developing an explanatory guide for dilution and administration of injectable medicines, which was made available to the clinical service. Collaborative strategies doctor-nurse-pharmacist can help to reduce errors in the medication process especially during his administration. It permits improvement of injectable drugs use, offering more security and better efficiency and contribute to guarantee ideal therapy for patients.

[Neonatal hyperthyroidism and maternal Graves disease]. / Hyperthyroïdie néonatale et maladie de Basedow maternelle.

The onset of Graves disease during pregnancy exposes the neonate to the risk of hyperthyroidism. The newborn must be monitored and treatment modalities known to ensure early treatment of the newborn. We report on the case of an infant born at term of a mother with Graves disease discovered during pregnancy. He was asymptomatic during the first days of life, before declaring the disease. Neonatal hyperthyroidism was confirmed by hormonal assays. Hyperthyroidism was treated with antithyroid drugs and propranolol with a satisfactory clinical and biological course. Neonatal hyperthyroidism should be systematically sought in infants born to a mother with Graves disease. The absence of clinical signs during the first days of life does not exclude the diagnosis. The duration of monitoring should be decided according to the results of the first hormonal balance tests.

[Respiratory disorders among late-preterm infants in a neonatal intensive care unit]. / Morbidité respiratoire des prématurés tardifs dans une unité de soins intensifs néonatale.

INTRODUCTION: The rate of infants born at 34-36 weeks of gestation has increased over the last 20 years. These babies are at higher risk of morbidity, particularly respiratory, than full-term infants are. The purpose of this study was to describe the respiratory morbidity of late-preterm infants and identify risk factors. PATIENTS AND METHODS: This was a descriptive, single-center study including 273 late-preterm infants born in a tertiary care hospital between July 2009 and December 2010. RESULTS: Of the mothers who delivered, 53.9% had morbidity. The cesarean-section delivery rate before labor was 20.9%; the main indication was fetal growth restriction (34%). Sixty-four percent of newborns had morbidity during their hospitalization and 23.1% suffered from respiratory distress. Mechanical ventilation was needed in 4.4% of the infants. Respiratory distress was mainly caused by early-onset sepsis or transient tachypnea. Ten infants presented with respiratory distress syndrome, of whom seven received a surfactant. Neonatal respiratory distress risk factors were gestational age, sex, and prelabor cesarean section (P<0.05). CONCLUSION: Late-preterm infants have an increased risk of respiratory disorders requiring ventilation. Elective cesarean should be limited if possible during this period.

Transverse properties of a Michelson mirror.

I calculate and compare the effective reflectivities of the first three Laguerre-Gauss modes incident on an asymmetric Michelson mirror (MM) using a power ratio. It is shown that the oscillation of a laser, made with a MM in a three-mirror configuration, can be switched from one transverse mode to another simply by controlling the phase delay between the two MM arms.

Divergence temporal dynamics of a Q-switched laser.

I address the influence of the direct coupling of the average lattice strains to the active ions on the pulse shape and the far-field beam spreading of a Q-switched laser. Calculations are made for the Cr(3+): sapphire system. The dynamic behavior of laser divergence as the pulse develops is studied without and with an internal aperture. The results can be used to search for similar effects in lasers involving other ions, such as Ti(3+) and Cr(4+).

Mode-volume enhancement in an apertured laser.

In a laser TEM(00)-mode selection by the use of a hard intracavity aperture gives rise to losses that are experimentally observable and to an increase in the fundamental-mode volume that is more difficult to observe. We use the parasitic resonances that are characteristic of multicavity lasers to demonstrate this volume enhancement in a He-Ne laser operating at 3.39 µm. The increase in mode volume in the apertured laser can increase the output power by a factor of 3 with respect to that of the nonapertured laser.

Principles of an intracavity polarimeter for measuring small optical anisotropies with an application to diffractive dichroism.

An intracavity polarimeter is described that is capable of measuring both weak birefringence and dichroism simultaneously. It uses, for the first time to our knowledge, polarization flips in a quasi-isotropic He-Ne laser. The laser operates at 3.39 µm. Calibration of the polarimeter is carried out by using the anisotropic properties of a tilted plate. As an illustration of the sensitivity, the diffractive anisotropy of an intracavity slit is measured.

Dichroism and birefringence in aperiodic coupled cavities and their influence on the polarization states of quasi-isotropic lasers.

We show that aperiodic coupled cavities may be designed to have a frequency-dependent complex reflectance that is anisotropic in phase (birefringent) and in amplitude (dichroic). The complex mean or average reflectivity may also be frequency dependent. As an illustration we show how such multicavity effects influence the stability of the polarization of light in quasi-isotropic lasers. Possible applications of the properties of aperiodic coupled cavities are suggested.